Sherlock Holmes Arsene Lupin and Irene Adler meet for the first time in Saint-Malo in 1870. They're supposed to be on vacation but destiny has other plans for them. Soon they're involved in a criminal vortex a diamond necklace disappears a dead man is found by the beach and a hooded figure appears and disappears all over the city. The police can only grope in the dark meaning someone else much crack this case...